Keep in mind that you're probably pumping a lot of exhaust fumes into the cabin. Not the least bit healthy when the windows are closed.

At the very least, plumb it out the back or make a simple side pipe.

 

i got a high flow cat put on by an muffler shop and i just want to know if my 5th and 6th ports are opening. I also have removed all emissions and put a plate over hole where emissions were. does that matter or what?

 

I was refering to no cat. Thats what I call a strait pipe.

 

oh ok..nevamind then :-)

 

Well, the stud on my exhaust manifold snapped off (long story) and I just decided to get a header and eliminate it altogether. It was my only mode of transportation at the time, so I had to drive it a few times. I made the mistake of redlining it once in first gear and my ears were ringing for several minutes. Keep in mind I also have the intake and exhuast ported as well. As for fumes, I always keep my windows down (no A/C) so I never had too much of a problem.

 

I did the same thing (RB header+presilencer) if you ever want to hear a loud rotary that combo in a garage would be a good way to go hahaha.

I tried it when i was about to start the rebuilt streeport in my car for the first time, my dad was 2 floors up and he said that everything was vibrating around. I had to put a damaged GReddy catback on just to dampen the sound.

 

they dont pull me over anymore..

i got atleast two dozen warrnings for exhaust last year, then they finnaly stoped.

cosmo turbo with no cats, resonators or anything and some cheapie strightthrough muffleers..

 

My friend and I gapped my mufflers from the Y-pipe about a month ago because we were bored and wanted to hear what it sounded like. The car sounds much deeper from 3.5K and bellow, very nice actually. And when I rev it to redline it's not high pitch sounding at all, it's actually quiter than when my car is sub 3.5K revs. There was no power gain, but I didn't do it for extra power. This is all done on a stock S5 NA exhaust system.